1. Field of the Invention
The present invention relates to a semiconductor apparatus and a circuit apparatus having the semiconductor apparatus mounted thereon.
2. Description of the Related Art
Recently, small-size electronic devices are widely spread, which are a cellular phone, a portable audio device, a PDA, a digital camera, etc. These electronic devices are demanded to be smaller, to have more functions, to have higher performance, etc. As a result, if an electronic device is manufactured, packaging technology, etc. are required for enabling higher density. See, e.g., Japanese Patent Application Laid-Open Publication No. 2002-93847.
In order to complying with such a requirement, recently, for example, an AM/FM tuner is constituted by one (1) package (semiconductor apparatus) and is provided as a commercial product which can be mounted on a portable electronic device. Although a package exists conventionally which stores almost all parts of a tuner as one (1) IC chip (semiconductor chip), for example, an inductor (coil), a varactor diode, etc. of a local oscillator circuit still must be mounted on a printed wiring substrate of an electronic device as an external part along with the package. In the package described here, an IC chip is electrically connected to a conductive path formed on the one side of a resin substrate and is then sealed with mold resin (insulating resin). On the contrary, recently, in order to store external parts into one (1) package, a pattern for a coil is formed on the other side (i.e., the under side of the package) of the substrate of the package, or a capacitor bank is incorporated into an IC chip, instead of a varactor diode which has relatively large dimensions. The capacitor bank is constituted by connecting a plurality of condensers having capacities differentiated by a predetermined size in parallel and the frequency is changed by sequentially switching the capacities with the use of software. In this way, by using the recent so-called “one-chip” package, a portable electronic device can also be equipped with a function of a radio easily.
By the way, in general, in order to maintain a good frequency characteristic of a LC circuit of the above-described local oscillator circuit, etc., the inductance characteristic of the coil must be stable. The inductance described here means the inductance of the coil stored along with the IC chip, etc. into the package mounted on a printed wiring substrate, for example. If the package is equipped on an electronic device, etc. by a user of the package, in order the inductance characteristic of the coil to maintain stability assumed on the manufacturer side, for example, predetermined mounting conditions are recommended from the manufacture side to the user side. The predetermined mounting conditions are, for example, to preliminarily form a dummy conductive pattern on a surface of the under side of the package, which is opposed to the coil, on the printed wiring substrate. In this way, the inductance of the coil is less affected by the printed wiring substrate.
However, for example, since the above-described dummy conductive pattern should be formed on a printed wiring substrate of the user side based on mounting conditions, etc. recommended from the user side, details of the shape, material, etc. thereof must be depending on the design of the user side. The accuracy of the package mounting position relative to the dummy conductive pattern must be depending on the operating accuracy of the user side. Therefore, the mutual inductance, etc. between the dummy conductive pattern and the coil are varied depending on the design and the operating accuracy of the user side. Consequently, the inductance characteristic and the stability assumed on the manufacturer side based on a single package may not be reproduced when mounting on an electronic device, etc. to be used on the user side. Alternatively, in order to reproduce the inductance characteristic and the stability, the user side may be forced to bear the burden in terms of the operation, etc. at the time of the package mounting.
In consideration of the above, it cannot be said exactly that the package requiring the above-described dummy conductive pattern is “one-chip” which does not need external parts at all, and the user side may end up being troubled.
In the single package, if an error is generated in the IC chip mounting position, etc. relative to the one side of the substrate described above, the operation of the IC chip may affect the inductance characteristic and the stability of the coil on the other side of the substrate. On the other hand, once sealed with insulating resin as described above, it is difficult to readjust the inductance of the coil in the package. Therefore, in order to maintain a predetermined inductance characteristic and stability of the coil, the operating accuracy must be improved when manufacturing the package and this is a burden on the maker side, which may result in a higher cost of the package.